Introduction: Recently, new sets of diagnostic criteria were proposed, including criteria by the ACTTION-American Pain Society Pain Taxonomy (AAPT) group and Fibromyalgia Assessment Status (FAS) 2019 modified criteria for fibromyalgia (FM). Here, we explored the performances of the AAPT criteria and modified FAS criteria for diagnosing FM compared to existing American College of Rheumatology (ACR) criteria.
Methods: We enrolled 95 patients with FM and 108 patients who had other rheumatologic disorders, including rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, and myofascial pain syndrome. All patients were classified using proposed criteria including the 1990, 2010, 2011, and 2016 versions of the ACR criteria.
Results: In patients with existing FM diagnoses, FM was diagnosed in 56.8% using the AAPT criteria and in 60.0% using the modified FAS criteria. However, FM was diagnosed in 37.9%, 97.9%, 90.5%, and 94.7% of those patients using the 1990, 2010, 2011, and 2016 ACR criteria, respectively. For the AAPT criteria, the sensitivity was 56.8% and the specificity was 94.4%. For the modified FAS criteria, the sensitivity was 60.0% and the specificity was 92.6%. The areas under the receiver-operating characteristic curve were 0.852 (95% confidence interval [CI] 0.801-0.903) for the AAPT criteria and 0.903 (95% CI 0.861-0.944) for the modified FAS criteria, which were lower than the existing ACR criteria.
Conclusions: Although the AAPT criteria and modified FAS criteria have simplified the diagnostic criteria to facilitate patient identification, their poor diagnostic accuracy will limit the adoption and spread of these criteria in routine clinical practice.
Keywords: Diagnostic criteria; Fibromyalgia; Performance.